I installed some RCA black plate 12AX7's in my DAC.
headrott
Posts: 5,496
I recently bought a quad of RCA black plate 12AX7 tubes and a quad of Mullard longplate 12AX7 tubes to further my study to find the best output tubes in my DAC located here: http://www.polkaudio.com/forums/showthread.php?119264-Fully-balanced-Buffalo-II-DAC-with-Tube-I-zator-tube-output.
To cut to the chase, I have found the RCA black plates the best overall output 12AX7's I have heard in this DAC. The tones are absolutely phenominal. Especially the midrange! The tones are very rich and make the output sound very "analog" coming from the DAC. The highs are very smooth and the bass is very tight. Also, these tubes are the most dynamic out of any 12AX7 I have heard. They are excellent for going from quiet music passages to extremely loud dynamic parts (i.e like the beginning part of "Blue Train" on Page and Plants' CD Walking Into Clarksdale going into the guitar and drum driven section with Plant singing "I've be waiting on a corner...I've been waiting for your sign now!"). The dynamic change is pretty dramatic. The RCA's make the sound "explode"! They reproduce the audio very nicely!
The only negative I can find with the RCA black plates is that the midrange is so "rich and creamy" that I feel a little detail is lost. This does not mean that the black plates are not detailed, but they are not as detailed as say Siemens 12AX7's or Telefunken ribbed plate 12AX7's. However, tonally the RCA's put those tubes to shame.
I thought I would let others looking for a great 12AX7 tube a heads up. Thanks for looking.
Greg
To cut to the chase, I have found the RCA black plates the best overall output 12AX7's I have heard in this DAC. The tones are absolutely phenominal. Especially the midrange! The tones are very rich and make the output sound very "analog" coming from the DAC. The highs are very smooth and the bass is very tight. Also, these tubes are the most dynamic out of any 12AX7 I have heard. They are excellent for going from quiet music passages to extremely loud dynamic parts (i.e like the beginning part of "Blue Train" on Page and Plants' CD Walking Into Clarksdale going into the guitar and drum driven section with Plant singing "I've be waiting on a corner...I've been waiting for your sign now!"). The dynamic change is pretty dramatic. The RCA's make the sound "explode"! They reproduce the audio very nicely!
The only negative I can find with the RCA black plates is that the midrange is so "rich and creamy" that I feel a little detail is lost. This does not mean that the black plates are not detailed, but they are not as detailed as say Siemens 12AX7's or Telefunken ribbed plate 12AX7's. However, tonally the RCA's put those tubes to shame.
I thought I would let others looking for a great 12AX7 tube a heads up. Thanks for looking.
Greg
Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
"I'm yet to hear a Polk speaker that merits more than a sentence and 60 seconds discussion."
![:\](https://forum.polkaudio.com/resources/emoji/confused.png ":\"){kind=small}
My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....
"Green leaves reveal the heart spoken Khatru"- Jon Anderson
"Have A Little Faith! And Everything You'll Face, Will Jump From Out Right On Into Place! Yeah! Take A Little Time! And Everything You'll Find, Will Move From Gloom Right On Into Shine!"- Arthur Lee